Coating unit for thin layers

在化学学院，计划安装一个涂层装置，用于由一氧化硅、二氧化硅、金、铬或钛制成的薄膜。可能的镀膜技术有溅射和电子束蒸发。涂层表面是制备生物杂化样品的第一个关键步骤，如固体支持的脂质双层、跨孔膜、细胞膜碎片和培养细胞单层。根据应用的不同，对涂层单元的要求是多方面的：i)用于电子显微镜、电化学和光学的纯净和光滑的超薄膜；ii)用于高稳定性、粘附性和表面功能化的多组分薄膜；以及iii)用于产生特定于几何形状的功能化的正交涂层。由于黄金涂层需要额外的钛或铬粘结层，因此必须选择在不通风的情况下对两种连续材料进行涂层，以确保表面无污染。因此，将需要两个溅射源或带有自动系统的蒸发装置来更换源。表面涂覆氧化硅和金，可以保留既定的制备方案。然而，二氧化硅还不可能被沉积，但需要充分探索基于荧光的技术。例如，与金和二氧化硅表面相比，荧光猝灭的影响大大减弱。此外，MIET(金属诱导能量转移)显微镜和声谐振器需要在二氧化硅表面下覆盖一层薄薄的金层，以实现荧光的特定猝灭或振荡器的驱动。由于表面粗糙度和厚度影响仿生样品的性能，因此这些参数的精确控制和重复性是必要的。这可以通过表面涂层工艺的自动化来实现。对于像MIET这样的先进荧光技术，均方根粗糙度小于1纳米的表面有利于将荧光增强和猝灭效应降至最低。此外，在跨孔膜的情况下，表面粗糙度增加了横向膜的张力，这影响了脂类、蛋白质和脂结构域的扩散。还需要薄的金属涂层，以确保电子显微镜样品的成像相当无伪影。为了保证跨孔膜的可重复制备，需要正交的表面涂层，即只需在顶部表面进行涂层。非常高的涂布室或倾斜角度的涂布程序可以实现涂层的正交性。

At the Faculty of Chemistry, it is planned to install a coating unit for thin films made of silicon monoxide, silicon dioxide, gold, chromium or titanium. Possible coating techniques are sputtering and electron-beam evaporation. Coated surfaces are the first crucial step in the preparation of biohybride samples like solid supported lipid bilayers, pore spanning membranes, cell membrane fragments and cultivated cell monolayers. The requirements for the coating unit are manifold depending on the application: i) pure and smooth ultrathin films for electron microscopy, electrochemistry and optics; ii) multicomponent films for high stability, adhesiveness, and surface functionalization and iii) orthogonal coating to yield a geometry-specific functionalization. Since gold coatings require an additional adhesive layer of titanium or chromium, the option to coat two consecutive materials without ventilation of the coating unit is mandatory to ensure contamination-free surfaces. Therefore, two sputtering sources or evaporation units with automated systems to change sources would be needed. Coating surfaces with silicon monoxide und gold allows retaining established preparation protocols. However, silicon dioxide has as yet not been possible to be deposited but is required to fully explore fluorescence-based techniques. For example, the effect of fluorescence quenching is greatly diminished compared to gold and silicon monoxide surfaces. Moreover, MIET (metal induced energy transfer) microscopy and acoustic resonators require a thin gold layer underneath the silicon dioxide surface to enable either defined quenching of fluorescence or driving of the oscillator. Since surface roughness and thickness influences the properties of the biomimetic samples, precise control and reproducibility of these parameters is necessary. This can be achieved by automation of the surface coating processes. For advanced fluorescence techniques like MIET, surfaces with a root mean square roughness below one nanometer nm are advantageous to minimize fluorescence enhancement and quenching effects. Furthermore, surface roughness enhances lateral membrane tension in the case of pore spanning membranes, which influences the diffusion of lipids, proteins and lipid domains. Thin metal coatings are also required to ensure rather artefact-free imaging of samples for electron microscopy. To guarantee reproducible preparation of pore spanning membranes, orthogonal surface coatings are required, i.e. only the top surface has to be coated. Very high coating chambers or glancing angle coating procedures can achieve orthogonality of coatings.